Perhaps you should try some spelling variations:
sach trien » sach tien, sach tren, sach thieu
trien hoat » tien hoa
dang khuan » khang khuan, dang khai, dang khanh
khoa thong » hoa thong, thoai thong, pho thong
tham thuoc » pham thuoc, tham thuc, nha thuoc
thuoc sach » hoc sach, nuoc sach, thuat sach
hoat dang » hoat dong, hoat hang, hoang dang
sach tham » sach nha
sach hang » sach han, sach nang, khach hang
hang khoa » dung khoa
toc sach » hoc sach, doc sach, nuoc sach
tu sach » thu sach, su sach, te sach

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: (( tu sach trien hoat dang khuan khoa thong ) or ( toc sach tham thuoc sach hang khoa thong ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( tu sach trien hoat dang khuan khoa thong ) OR ( toc sach tham thuoc sach hang khoa thong )).
• Adding a wildcard symbol may retrieve word variants: (( tu sach trien hoat dang khuan khoa thong ) or ( toc sach tham thuoc sach hang khoa thong ))*.